Fluorescent tube lock pin



Sept. 2, 1958 M. H. PARDUE 2,850,710

FLUORESCENT TUBE LOCK PIN Filed Dec. 28, 1954 I N VEN TOR.

ATTD R N EYE Patented Sept. 2, 1958 FLUORESCENT TUBE LGCK PEN Martin H. Pal-due, Nashville, Tenn.

Application December 28, 1954, Serial No. 477,999

2 (Ilaims. (Cl. 339-54) This invention relates to safety locking devices for retaining fluorescent tubes in fixtures to prevent tubes accidentally dropping from sockets, and in particular, a key adapted to be inserted through the slot of a tube retaining socket whereby after placing pins on the ends of tubes through said slots and turning the tubes with the pins through an angle of 90 degrees a key is inserted in the slot to prevent the tubes being accidentally rotated to such positions that the pins may pass downwardly through the slots.

The purpose of this invention is to provide a locking 1 key for preventing turning of fluorescent tubes in sockets to prevent accidental displacement of the tubes in which means is provided for frictionally or resiliently retaining the keys in position. 7

Various types of locking devices have been provided for preventing accidental displacement of fluorescent tubes from lighting fixtures, however, some of such locking devices require changes in the fixtures or tubes and where keys are freely positioned in the slots they are adapted to be displaced by shock, jars, or vibrations, such as are common in building structures. With this thought in mind, this invention contemplates a locking key adapted to be inserted in a vertically disposed slot of a fluorescent light tube fixture in which means is provided for extending the width of the key above and below the centrally positioned section of the socket or in the circular slot in which the pins of the tube are positioned.

The object of this invention is, therefore, to provide means for providing enlarged sections in a key for securing fluorescent light tubes in fixtures in which the enlarged sections are positioned to register with the circular slot in which the pins are turned in mounting a tube in a fixture.

Another obfiect of the invention is to provide a locking key for retaining fluorescent light tubes in fixtures in which the key is adapted to be inserted in slots of fixtures now in use without changing the fixtures or tubes.

Another important object of the invention is to provide akey adapted to be inserted in a slot of a socket of a fluorescent light tube fixture for preventing accidental displacement of the tube in which a pair of arms extend from the head of the key to provide supporting means below the end of a tube which is held in a fixture in which the key from which the fingers extend is positioned.

A further object of the invention is to provide a safety key for securing fluorescent light tubes in fixtures in which the key is of a simple and economical construction.

With these and other objects and advantages in view, the invention embodies a key having a shank extended from a head with portions of the shank enlarged and with the enlarged portions positioned to correspond with the circular slot of a fixture in which pins on the end of a tube travel whereby the key is adapted to be retained in position in a vertically disposed slot in the socket of a fixture until the key is manually withdrawn from said slot.

Other features and advantages of the invention will appear from the following description, taken in connection with the drawing, wherein:

Figure 1 is an exploded view looking toward the inner surface of a fixture adapted to support an end of a fluorescent light tube showing a key for retaining the tube in the fixture withdrawn and positioned below the fixture.

Figure 2 is a view similar to that shown in Figure 1 showing the key in the fixture.

Figure 3 is a cross section taken on line 33 of Figure 2 also showing the key positioned in a slot of the fixture.

Figure 4 is a perspective view illustrating a fixture for retaining fluorescent light tubes showing a modification in which a key for locking a tube in a fixture is provided with angularly disposed arms whereby with the arms positioned below a tube the tube will drop into the arms upon accidental displacement thereof from the fixture.

Figure 5 is an elevational view similar to that shown in Figure 2 showing the key, illustrated in Figure 4, in the socket of the fixture.

Figure 6 is a vertical section through the fixture shown in Figure 5 illustrating the positions of the arms which extend below the tube and showing a tube in the fixture, the tube being shown in broken lines.

Figure 7 is a perspective view illustrating a key of a modified design wherein the key is adapted to be frictionally retained in a slot of the fixture.

Figure 8 is a view, similar to that shown in Figure 2, showing the key illustrated in Figure 7 positioned in the fixture.

Referring now to the drawing, wherein like reference characters denote corresponding parts, the improved fluorescent light tube locking key of this invention includes a head 13 having a shank formed with arms 11 and 12 in which the ends of the arms are provided with arcuate flanges 13 and 14, respectively, and the intermediate parts are provided with enlarged portions 15 and 16.

With the parts formed as illustrated in Figures 1, 2, and 3, the key is formed with a strip of material bent, at a point midway of the length thereof, to form the loop it which provides a head and, from the head, the arms of the strip of material contact at a point 17 and extend from the point 17 to the tips 13 and 14-. The arms may also be provided with shoulders 18 and 19 that are positioned to engage lower surfaces 20 and 21 at the lower end or" an arm 22 of a fixture 23, the inner face of the arm 22 being provided with an annular recess 24 in which pins 25 and 26, extended from the end of a fluorescent tube, are adapted to turn.

In assembling a tube in a fixture, the pins 25 and 26 are positioned in a vertical plane whereby the pins are adapted to extend through a slot 27 in the lower end of the arm 22 and also through a slot 28 between segments 29 and 30 of a core, or the like, positioned in the center of the recess 24.

With the parts formed as illustrated and described, the arms of the key are inserted through the slots 27 and 23 whereby the flanges 13 and 14 spread into the circular groove 24, as shown in Figure 2, with the enlargements l5 and 16 positioned to bulge into the recess and with the shoulders 18 and 19 positioned to substantially engage the inclined surfaces Zfi and 21.

With the flanges 13 and 14 positioned in the annular recess 24 above the segments 29 and 3t) and with the enlarged portions 15 and 16 extended into the annular recess below the segments 29 and 3d, the key is secured in position and with the key positioned, particularly as shown in Figure 2, it will be impossible for the pins 25 of the'loop or head, as indicated by the numeral 10.

and '26 to work into positions above the slot 27 so that a tube may drop fro a fixt re- The key, therefore, definitely secures a fluorescent tube, such as that indicated by the numeral 31, in position in a fixture.

:In the de i n i us rat d in Fi ures 1 a d 6, key, having a head 32 similar to the head 11}, and having arms 3' an 34 Simi a wil s- 2 511 and. 1. pr ide wi 'pu w dly r x ende n msfi a d 3. h h x en p andsq W 3? n h t eweb 'pe ti n dr as shown in Figure 6, the arms 3 5 ;aud 3e extendbelow a fluorescent tube, such as the tube 31, wherebyupon ur QfPa t th b k t 9r xture t e tu e. d p upon the arms 35 and 36 and is retained in position he b -f e web 31 s te ra ly co n ct d o he ea 32, as shownat point; 38, and the arms are provided with outwardly bulging sections39 and 40 similar to the sides It will be understood, however, that the arms 35 and 36 may be of any suitable design. a

With the key formed, as illustrated in Figures 4, 5 and 6, the arms 33 and 34 are inserted in the slots 27 and 28 of a fixture, as shown in Figure 1, with flanges 41 and 42 extended into the upper parts of the annular recess 24 o the $3 2. th? fix r and em and 44 extended into the lower portion of the recess similar to the parts and 1d of the design shown in Figures 1, 2 and 3 By this means the extended arms 35 and 36 are supported by the' arms of the key and the arms of the key are retained in end portions o f a fixture. with resiliency inherent therein and with the flanges 41 and 42 and enlarged portions43 and 44. V

In the design illustrated in Figures 7 and 8, the key is formed of a solid piece of plastic, or other suitable material, having an enlarged portion 45 positioned to snap V he k y is re ained imposition and with the key in P sition.

' work out of the openings of the arm 22 of the fixture.-

4 r in the lower part of the annular recess. By this means it is substantially impossible for the pins and 26 to from the depending arms of-the fixture or recess therein.-

Thus, it will be seen that there has been provided a new article, of manufacture, wherein therefis provided a locking key for retaining. a fluorescent tube in a fixture, and wherein the locking key is'shaped to include a looped portion which defines an enlarged head 10, Figure 1." A pair of similar side sections 11 and 12 extend from the head 10, and the free ends of the side sections terminate in outwardly flaring oppositely extending end portions 13 and .14. The. side; sections further include enlarged por' tions 15 and 16, and the enlarged portions 15 and 16' into the upper part of the circular recess 24 of the arm 22 of a fixture, an enlarged portion 46 positioned to correspond with the lower part'of the circular recess, a

'thin intermediate portion 47 connecting the portions 45.

and 46, and athin lower'portion 48 connecting the lower end of the key to a head, or tab 49 having knurled surfaces asindic ated by the numeral 50[ With the parts 45 and 46 having slightly greater; width than the width of the slots 27 and 28, the key may readily be snapped into position and with the parts 45. and 4e in the open areas of the annular recess 24 the key will be retained in position, as shown inFigure 8, thereby preventing rotation of the pins 25 and 26, orturningmovements of the tube.

The arrn22 of the light fixture is provided with spring clips 51 and 52 which are provided with notches 53 and '54, respectively, and upon rotation ofa fluorescent tube with pins .irithe circular recess 24, the'pins25 and 26 snap into .the'notches 53; and '54 whereby the tube is re-.

tained inpo on with the pins 2 5 and 26 in a substantially."horizontaliplaner fThe pins 25 and 26 of a tube are in's'er'ted'through the.slot 2 7 with the upper pin passing through theslot 23 and uponrotationof'the tube the 7 pins snap'T'info the notchesf 53 and 54: of the spring} clips. .With'th'e tube this position, the key is inserted throughtheslots 27- and 28, as shown in Figures 2, 5, and'f8 wherein the' fclipsor. flanges atthe upper end of thestem or shank of the key spread into the upperpart of'the annular recesswith the enlarged portions, such "as the parts 15 and or the section 45 are arranged intermediate the ends of the side sections. The side sections are provided with shoulders 18 and 19, and these shoulders are arranged contiguous to thehead;

Asshown inthe drawings suchas Figures 4, 5' and6 there is further provided asupport member which is in:

dicated'by' the numeral 37-, and'the support member. 37: includes a curved web which is secured to the head of the locking key, and arms '35 and 36, extend from this .web, the arms being provided with intermediateofiset portions 39' and 40.

It will be understood that modifications, Within the scope of the appended claims, may be made in'th'e design and arrangement of the parts without departing from the spirit of the invention. 7

What is claimed is: 1 1. 'As a new article of manufacture, a locking key;

for retaining a fluorescent tube in a'fixture, said locking: key being shaped to include a looped portion which-idea fines an enlarged head, a pair of similar side sections EX'. tending from said head, the free ends of said side sections" terminating inoutwardly flaring oppositely extending end, portions, said side sections further including enlarged portions, said enlarged portions being 7 arranged intermediate the ends of the side sections, said side sections being provided with shoulders, said shoulders being ar-' ranged contiguous to said head. 2. The structure'as defined in claim land further: in-# cluding a support member which includes a curved web' secured to said head, and arms'extending from said web, said arms being provided with intermediate oflset portions.

References Cited in the tile of this patent NIT D STATES PATENTS 

